If you own a plug-in hybrid or electric car, it looks like you'll get to keep using the carpool lane for the next few years. State lawmakers have taken another step to extend the program. But not everyone likes the idea.

More incentive for Californians to buy cleaner cars: a free pass as a solo driver in the carpool lane until 2019.

The state legislature approved a bill that would extend those green stickers for plug-in hybrids and white stickers for electric cars for three more years.

These greener vehicles can help clean the air because they emit 34 percent fewer greenhouse gasses and 75 percent less smog.

"California has always been leading the way when it comes to lowering our carbon footprint," said Assm. Richard Bloom (D-Santa Monica). "These standards will entice Californians to utilize the most environmentally friendly vehicles."

At a cost of up to $10,000 more than a regular hybrid, sales of the next-generation of clean vehicles have been slow, and tax credits have not helped. As of mid-July, DMV has issued fewer than 16,000 green stickers since January 2012.

While the goal of cleaner air is worthwhile, opponents don't like opening up the carpool lane to people who are driving alone.

"I think most people out there would love to be able to get home from work in a timely fashion. That was the original intent, was to reduce congestion, encourage people to carpool, and then they can spend more time with their families," said Assm. Tim Donnelly (R-Twin Peaks).

During the last program that gave the same privileges to Prius drivers with now-expired yellow stickers, the federal government warned California that too many solo drivers were clogging the HOV lanes and threatened to cut transportation funds. This time, lawmakers have learned their lesson.

"We do, in fact, leave some wiggle room with the Department of Transportation to kind of let them look at how do we moderate the use of these particular stickers," said state Sen. Leland Yee (D-San Francisco).

One more procedural vote before the green and white sticker programs head to the governor's desk. Gov. Brown generally supports measures that help fight climate change.